Incandescent-lamp socket.



No. 689,932. Patented Aug. 20, IQIDI.

N. MARSHALL. INCANDESCENT LAMP SOCKET.

(Application filed Mar. 18, 1901.)

(No Model.)

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NORMAN MARSHALL, OF NEIVTON, MASSACHUSETTS.

lNGANDESCENT -LAMP SOCKET.

SPECIFICATION forming part of Letters Patent No. 680,932, dated August 20, 1901.

Original application filed August 8,1900, Serial No. 26,234. Divided and this application filed March 18, 1901. Serial No. 61,661. (No model.)

To ctZZ whom it may concern.-

Be it known that I, NORMAN MARSHALL, of Newton, in the county of Middlesex and State of Massachusettshave invented certain new and useful Improvements in Incandescent-Lamp Sockets, of which the following is a specification.

My invention relates to incandescent-lamp sockets, and more especially to the metallic shell which incases and supports theinsulating-base upon which the current-carrying parts of the socket are mounted; and its object is to provide a shell formed in two partsa cylindrical part and cap partwhich is simple in construction, which may be conveniently and cheaply manufactured, and in which the parts are securely held together when connected and may be readily connected or disconnected in assembling or separating the parts of the socket. Heretofore in shells of the general character referred to it has been customary to secure the parts together by providing bayonet-joints in the cylindrical part of the shell, arranged to engage screws carried by the cap, which screws could be tightened after the parts were assembled to securely hold the cap and body together. These screws have been threaded into arms or ribs extending downward within the cap from a yoke secured to the inner end of a nozzle or bushing at the top of the cap through which the line-wires pass. In the shell embodying the present invention the construction is simplified and cheapened by securing metal studs in the Wall of the shell, into which the screws are threaded and which provide an effective, simple, and reliable means for engaging the threads of the screws and holding the same in place. I prefer to secure the studs in place by forming an irregular or polygonal hole in the thin wali of the shell, into which the stud is expanded, and I also prefer to form a shoulder on the stud and to turn over the end of the stud to clamp the wall of the shell between said end and the shoulder. This construction is more facturin gthe shells.

secured to either the cylindrical part of the shell or to the cap, but I prefer to secure the screws to the cylindrical portion and to form the bayonet-slots of the bayonet-joints in the cap, and I have shown this form of the invention in the accompanying drawings, in which- Figure 1 is an elevation, partly in section, showing a socket embodying the features of the present invention. of the cylindrical part of the shell with the screws and caps removed. Fig. 3 is a plan view of Fig. 2. Fig. at is an elevation of the cap. Fig. 5 is an enlarged view of the upper end of the cylindrical part of the shell. Fig. 6 is an enlarged detail sectional view. Figs. 7 and 8 are enlarged details of the stud.

The shell is in two partsa cylindrical part A and a cap Bformed of thin sheet metal, and when the parts of the socket are assembled this shell incloses the insulating-base O of the socket, as indicated in Fig. 1. The cap B is provided at its upper end with bushing or nozzle 13', secured in an opening through the cap and provided with a screw-threaded opening by which the socket may be secured to a fixture and through which the line-wires pass to the terminals of the socket. The cap is also provided with two bayonet-joint slots 79, which are arranged to engage the shanks of screws 0, carried by the cylindrical part A. The screws are connected with the shell by being threaded in studs ct, secured in the walls of the shell. In securing these studs in the walls of the shell I form irregular holes a in the shell, the holes preferably being polygonal, as shown in Fig. 5. The hollow studs are provided with an end of reduced diameter, forming a shoulder at 0. for engaging the walls of the shell. The reduced end of the stud is passed through the irregular hole in the shell and the part which extends through the wall is turned over, thus clamping the wall between the shoulder a and the turned-over part at The stud is also expanded within the hole Z) into the irregular parts of the hole, so that said stud will be securely held from turning in the wall of the shell. The stud may be quickly and conveniently secured in place by the action of a punch shaped to both expand the part within the wall of the shell and Fig. 2 is an elevation to turn over the part extending through the wall. The stud is tapped either before or after being secured in place to engage the screw-thread in the screw a. When the cap is in place, the parts maybe held securely together by tightening the screws a, the walls of the cap being clamped by the heads of the screws. The insulating-base C is provided with grooves 0, extending longitudinally thereof, through which the inwardly-projecting parts of the studs pass in assembling the parts of the socket and which cooperate with said studs to prevent the shell and insulating-body turning with relation to each other when the parts are assembled.

What I claim, and desire to secure by Letters Patent, is-

1. A metallic shell for incandescent-lamp sockets formed in two separable parts, one of said parts having irregular holes through its wall, shouldered studs expanded within said holes and having their ends turned over to clamp the wall between the turned-over ends and the shoulders, screws threaded in said studs, and the other part having bayonetjoint slots for engaging said screws.

2. A metallic shell for incandescent-lamp sockets comprising a cylindrical part A, irregular holes a in the part A shouldered studs a expanded within said holes and having the end turned over to clamp the wall between the shoulder a and turned-over end a screws a threaded in said studs, and a cap B having bayonet-joint slots 1) for engaging screws a.

3. In a socket for incandescent lamps the combination with an insulating-base provided with groovesextendin g longitudinally thereof, of a metallic shell having a cylindrical part A and cap B, inwardly-projecting studs secured in the wall of the part A arranged to register with said grooves, screws threaded in said studs, and bayonet-joint slots in said cap for engaging said screws.

4. A metallic shell for incandescent-lamp sockets formed in two separable parts, one of said parts having irregular holes through its wall, studs expanded within said holes, screws threaded in said studs, and the other part having slots for engaging said screws.

5. A metallic shell for incandescent-lamp sockets formed in two separable parts of thin material, one of said part-s havinginternallyscrew threaded studs secured in its wall, screws threaded in said studs, and the other part having slots for engaging said screws.

In testimony whereof I have affixed my signature in the presence of two witnesses.

NORMAN MARSHALL.

Witnesses:

E. M. BAKER,- O. A. SANDERS. 

